Let  be Three Unit Vectors Such That Angle Between  is  If  then Cos α + Cos β + Cos γ = 

Let  are two vectors inclined at an angle of 60^o. If  then the angle between   

If  are unit vectors such that  is also a unit vector, then the angle between , is

If  are unit vectors such that 

If  are unit vectors such that  and  then 

If  are unit vectors inclined to x-axis at angles 30^o and 120^o, then  equals

If  are three vectors such that 

Let  be three vectors such that  and  If 

If two out of the three vectors  are unit vectors such that  then the length of the third vector is   

Let  be three unit vectors such that  and  If  makes angles δ, β with  respectively, then  is equal to

Let  be three unit vectors such that angle between  is  If  then cos α + cos β + cos γ =